For some kind of projects, it could be essential to be able to select, for a given audio player, the audio output device among available ones! The interest is to set the audio output of one player to, for example, the internal speakers or Airplay/Airport network device, and the audio output of another player, running asynchronously, to a Bluetooth device.

The best use could be a tool for presentations/conferences where the main audio (player 1) is sent to the public, and an audio prompting (player 2) only to the presenter/speaker's Bluetooth headset !

Other applications : learning and teaching …

Even better : using revSpeak text-to-speech command to send audio prompts to the headset ! But, for that, is it possible to select an audio output device (Bluetooth) for revSpeak ? I'm not sure! It would be too good! Do not dream, Éric!